Air separation device and air separation method
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The conventional air separation devices face difficulties in starting the high-pressure and low-pressure columns and the argon column due to the lack of indirect heat integration between these columns, which affects the rectification conditions and separation efficiency.
Innovation Solution
The air separation device includes a high-pressure column, a low-pressure column, and an argon column with indirect heat-exchangers that facilitate heat exchange between nitrogen and oxygen gases, allowing for the easy start-up and efficient separation of nitrogen, oxygen, and argon by adjusting the opening degrees of valves in the heat-exchange passages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the argon column is operated at the same pressure as the low-pressure column, then the device complexity is reduced, but the rectification condition of the low-pressure column deteriorates and argon separation becomes difficult
Solution Approach 1:
The patent applies parameter changes by operating the argon column at a different pressure (either higher or lower) compared to the low-pressure column. This pressure differentiation changes the operating parameters of the system to achieve better rectification conditions and argon separation, resolving the contradiction between device simplicity and separation precision.
2Manufacturing precision
If the oxygen concentration of the gas fluid vaporized by the argon column condenser is increased, then the rectification condition of the low-pressure column is improved, but the saturation temperature of the gas fluid becomes higher than that of argon gas making indirect heat-exchange impossible
Solution Approach 1:
The patent changes the pressure parameter of the argon column operation, which consequently changes the saturation temperature of argon gas. By adjusting the pressure, the saturation temperature is optimized to enable indirect heat-exchange while maintaining good rectification conditions in the low-pressure column.
3Use of energy by moving object
If the low-pressure column and high-pressure column are heat-integrated by an indirect heat-exchanger, then the energy efficiency is improved, but the device complexity and difficulty of starting the argon column increase
Solution Approach 1:
The patent extracts the heat-exchange function from the mandatory integration between low-pressure and high-pressure columns. By making the heat-exchange integration optional rather than required, the system achieves energy efficiency when needed while avoiding the complexity and startup difficulties that would result from mandatory integration.
4Shape
If the argon column is located between the high-pressure column and low-pressure column, then the spatial arrangement is optimized, but it becomes difficult to start the high-pressure and low-pressure columns first and then the argon column
Solution Approach 1:
The patent segments the startup process into distinct phases with controllable sequences. By providing multiple passages and control mechanisms, the system allows flexible startup sequences where the high-pressure and low-pressure columns can be started first, followed by the argon column, despite the optimized spatial arrangement of the argon column being located between the other two columns.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enables easy start-up and stable operation of the air separation device, improving the separation efficiency and preventing pressure drops that could affect the air purifier's performance.
Implementation Method 1
a first indirect heat-exchanger which indirectly heat-exchanges between the argon gas and the low-pressure liquefied oxygen, liquefies the argon gas to generate liquefied argon, and vaporizes the low-pressure liquefied oxygen to generate low-pressure oxygen gas
Implementation Method 2
liquefies the argon gas to generate liquefied argon
Implementation Method 3
vaporizes the low-pressure liquefied oxygen to generate low-pressure oxygen gas
Implementation Method 4
a second indirect heat-exchanger which indirectly heat-exchanges between the high-pressure nitrogen gas and the medium-pressure liquefied oxygen, liquefies the high-pressure nitrogen gas to generate high-pressure liquefied nitrogen, and vaporizes the medium-pressure liquefied oxygen to generate medium-pressure oxygen gas
Implementation Method 5
liquefies the high-pressure nitrogen gas to generate high-pressure liquefied nitrogen
Implementation Method 6
vaporizes the medium-pressure liquefied oxygen to generate medium-pressure oxygen gas
Implementation Method 7
a high-pressure column which distills high-pressure raw material air at a low temperature and separates it into high-pressure nitrogen gas and high-pressure oxygen-enriched liquefied air
Implementation Method 8
a low-pressure column which distills the high-pressure oxygen-enriched liquefied air at a low temperature and separates it into low-pressure nitrogen gas, low-pressure liquefied oxygen, and argon-enriched liquefied oxygen
Implementation Method 9
an argon column which distills the argon-enriched liquefied oxygen having a pressure higher than the pressure of the low-pressure column at a low temperature and separates it into argon gas and medium-pressure liquefied oxygen
Data Source
AI summary
An air separation device for distilling air at a low temperature, includes a high-pressure column to separate high-pressure raw material air into high-pressure nitrogen gas and high-pressure oxygen-enriched liquefied air; a low-pressure column to separate the high-pressure oxygen-enriched liquefied air into low-pressure nitrogen gas, low-pressure liquefied oxygen, and argon-enriched liquefied oxygen; an argon column to separate the argon-enriched liquefied oxygen having a pressure higher than the pressure into argon gas and medium-pressure liquefied oxygen; first and second indirect heat-exchangers; first and second gas-liquid separation chambers; a first/second passage which communicates the gas/liquid phase of the low-pressure column and the gas phase of the second gas-liquid separation chamber; and a first/second opening/closing mechanism located on the first/second passage.